1. Obesity and Weight Loss

Flavonoids are a category of antioxidants found in virtually all plant-derived foods, especially fresh vegetables, fruits, legumes and whole grains.

This observational study in 9,551 US adults found that those who consumed a lot of flavonoids were less likely to be obese. Additionally, a high flavonoid intake was associated with lower levels of C-reactive protein, which is a marker of inflammation.

Barley beta-glucan is a water-soluble, viscous fiber thatâ€™s similar to oat beta-glucan, which has been linked to various health benefits.

This controlled study in 100 Japanese adults showed that eating a diet high in barley beta-glucan, or 4.4 grams per day for three months, led to greater weight loss than garcinia cambogia which doesn’t contain any beta-glucan.

2. Blood Sugar Control and Diabetes

This controlled study in 65 vitamin D-deficient, overweight or obese adults showed that a one-time 100,000-IU dose of cholecalciferol followed by a 4000-IU daily dose of cholecalciferol for four months did not affect insulin sensitivity or production.

This controlled study in 48,835 postmenopausal women aged 50â€“79 found that following a low-fat diet consisting of 20% of calories from fat for eight years did not affect the risk of heart disease overall, compared to a usual diet.

However, women without prior heart disease appeared to benefit from the diet, although the health improvements were offset by an increased risk of stroke.

This meta-analysis of controlled studies concluded that replacing saturated fat with polyunsaturated fat (mostly omega-6) probably doesnâ€™t reduce the risk of heart disease, death from heart disease or death from any cause.

Some previous meta-analyses have concluded that replacing saturated fat with omega-6 fat has benefits for heart health. However, the researchers pointed out that they may have included inadequately controlled studies.

This review and meta-analysis of observational studies concluded that contaminants that form when meat is cooked at a high temperature may be responsible for meatâ€™s association with an increased risk of colon cancer.

5. Brain and Mental Health

Multiple sclerosis (MS) is a neurodegenerative disease. Itâ€™s characterized by a variety of neurological symptoms, ranging from impaired memory and mental problems to impaired eyesight, muscle weakness and lack of coordination.

This review concluded that a high intake of vitamin D may reduce the risk of MS and improve symptoms. Additionally, a few studies show that low vitamin B12 levels are associated with worsened MS symptoms.

This observational study in 1,468 older, postmenopausal women found that a high self-reported intake of vegetables was linked to a lower risk of bone fractures. In contrast, fruit intake was not associated with fracture risk.

When the researchers looked at different vegetable types, onions and cruciferous vegetables appeared to be the most protective. For instance, a high intake of cruciferous vegetables reduced fracture risk by 28%, compared to low intake.

8. Arthritis

Synbiotics are supplements containing both probiotics and prebiotics (beneficial bacteria and the fiber that nourishes them). Their anti-inflammatory effects might benefit people with rheumatoid arthritis (RA).

This two-month, controlled study in 54 adults with RA found that daily synbiotic supplements significantly improved insulin sensitivity, reduced levels of the inflammatory marker C-reactive protein (CRP) and alleviated the symptoms of RA.

Previous observational studies indicate that high levels of vitamins C and D may reduce pain and improve function in people with knee osteoarthritis (KO).

This observational study in people with KO found that vitamin D supplements were strongly linked to better function. However, high vitamin D levels were associated with greater pain, whereas vitamin C wasnâ€™t linked to any measures of KO.

This controlled study in 80 overweight or obese, pre-diabetic women found taking 3 grams of cardamom supplements per day for two months significantly reduced markers of inflammation (CRP and IL-6) and oxidative stress (malondialdehyde).

10. Longevity and Healthy Aging

This observational study in 103,256 Swedish adults showed that eating a lot of non-fermented dairy (ND) and butter was linked to a 32% greater risk of death from any cause, compared to eating ND only once per week.

The risk of death was lower among those who consumed mostly medium or low-fat milk. In contrast, fermented milk products, such as yogurt and cheese, were associated with a lower risk of death.